Minute
particles of organic matter, weathered rock and plant and
animal life is what makes up the soil that we all know and
use. Plant growth depends on us using the very best soil
for the job.

Soil supports plants and provides them with
nutrients, air and water. Not having the right kind of
soil to hand does not mean that it cannot be adapted to
suit your needs. Waterlogged soil can be drained and vice
versa.

A vast supply of minerals and additives that can
change your soil's properties are available to buy online
or at any
good garden retailers. Even if you do not have a garden
your plants can still thrive indoors by using the right
potting compost.

Soil Classification

We
classify most soils by their clay, sand and silt content.
These mineral particles change the physical and chemical
aspects of the soil. Clay soils are generally more fertile
than sand or silt soils but they are heavy and tightly
formed, usually causing them to go hard in the sun. Clay
soils have slow drainage and warm up slowly in Spring.
Silt and sandy soils have a low clay particle count and
are therefore not as water retentive. Silt soils are more
fertile and hold water better than sandy soils but they do
compact. Sandy soils are free draining and not heavy at
all. They need regular feeding and watering but can be
improved by adding organic matter. Loam soils have the
correct balance of mineral particles resulting in good
retention and drainage and high fertility. When wet acid
conditions prevent decomposition of organic matter peat is
formed. Chalky soil is free draining and alkaline and
allows full decomposition of matter.

Soils are
divided into three layers, topsoil, subsoil and a layer
derived form the parent rock. Topsoil is generally darker
then the others due to it containing the most nutrients
and organisms. Organic matter is added by leaf fall or
added artificially. Subsoil should be lighter than
topsoil, if they are similar in appearance then the
topsoil may have a deficiency in matter.

Soil
Identification

The best way to identify your soil is to
feel it. By rubbing some moist soil between your fingers
you should be able to feel the differences between the
types. Clay and loamy clay soils feel heavy, sticky and
are malleable. When laid out flat it will show a shiny
surface. Silt soils will feel silky to touch. A silty loam
soil may be pressed down and imprinted with your finger.
Sandy soils feel bitty and are not malleable at all. They
can not be moulded into shapes or stuck together, although
a sandy loam may be able to.

Soil
pH

Knowing the acidity or alkalinity of your soil may be
crucial to growing healthy plants. Certain plants need a
certain pH balance in their soil to thrive fully. Finding
out what soil you have can be done using a few methods,
and changing the pH balance can also be done. Certain
weeds and plants growing in a garden can indicate the type
of soil that you have. Rhododendrons, foxgloves and
heathers all indicate acidic soil. Viburnum, yucca,
cotoneaster (rose family) and forsythia (olive family), to
name a few, thrive in alkaline soil. The pH of soil is
usually based on its calcium content. Using electronic or
soil testing methods to find out the pH balance of your
soil is also effective. When a pH is below 7 it is acidic,
7 is neutral and above 7 is alkaline. All soils lose some
of their calcium content when it is washed away by water.
Alkalinity can be introduced through liming or using a
lime rich compost. When testing your soil ensure to test
several different areas of the garden, and remember that
if you have limed any areas the results of your testing
may be inconclusive. Maintaining optimum pH of 5.5 to 7.5
can be easy as long as you know your starting level and
what to do to achieve your optimum level. Soils below 5.8
will need liming. This is worthwhile doing if you wish to
improve your vegetable crop but is not so worthwhile for
just plants. It is much easier to choose plants suitable
for the conditions of the soil. If you have made the
decision to lime an area then go for ordinary calcium
carbonate. It is safe to use and easy to handle. Other
methods such as quicklime - calcium oxide and hydrated
lime - calcium hydroxide can be caustic, hard to handle
and you could easily over lime the area. If planting
in soil with a level over 7 top-dress with sulphate of
ammonia and mulch with acid compost to reduce the pH
level. This is only short term though and will need to be
repeated following manufacturers guidelines.

Soil pH affects a great
many things, it is not just the plants health that is
determined but also how the pests and diseases thrive.
Acidic soils attract wireworms and clubroot but deter
worms. Alkaline soils are where potato scab and chlorosis
of leaf vegetables most appear. A pH level of 6.3-6.8 is
also the level preferred by most soil bacteria. However
fungi, moulds and anaerobic bacteria have a wider spectrum
of tolerance and can multiply at lower levels. In
order to maintain maximum soil fertility you have to have
certain organisms such as beneficial bacteria and fungi
present. Mites help along the process of matter breakdown
and certain worms such as microscopic and nematodes help
with pests, although some are pests themselves. Earthworms
contribute to aeration and drainage by passing the soil
through their bodies and binding it into crumbs.

Soil
Sterilisation

Some pests such as nematodes and honey
fungus, that are found in soil can be so resistant to
barrier methods and aggressively persistent that soil
sterilisation may be the only answer. This method should
only be used after all other methods have been exhausted
as it is indiscriminate between the good pests and the bad
pests. This may lead to future issues with harmful pests
who may revisit the garden to find there are no natural
predators there to keep the numbers down. Soil
sterilisation can only be carried out by a trained
operator as it is extremely poisonous and so it will cost
you money to have it done. The chemical is applied to the
soil and it seeps through the soil pores. The soil is then
covered with plastic to stop the gases from getting out.
It will then take approx 3-4 weeks before the soil is
ready to be planted in.

Soil
Cultivation

We all use our favoured methods of
cultivating soil, be it digging, weeding or adding soil
enhancements and these are all paramount to our plant's
life spans. Weeds have to be eradicated before they strip
the plants of all the vital nutrients that they need. When
left to grow weeds compete for all of life's essentials,
water, light and space. They may also carry diseases that
can destroy some of the plants in our gardens. Weeding
regularly by hand is the best method as it means that you
can get the whole of the plant up and you will cause the
least amount of stress on your surrounding plants. Digging
up soil to prepare for planting, or digging round existing
plants, can be extremely beneficial for maintaining
drainage and aeration. Additional materials may be
added to improve conditions if needed. Generally single or
double digging with a spade is sufficient to improve soil
conditions. Garden beds however have a smaller area to
work with and usually packed with plants so you will find
that a fork is better used in these conditions. Digging
can have its downside too though, it can decrease the
breakdown of matter which in some soils can reduce
fertility. And if not dug consistently some soils may
compact with time which causes poor aeration and drainage.
Dig in autumn when the soil is exposed to snow and frosts
as this will help to break it down. Do not dig wet, heavy
soil as this can cause severe damage. Forking is best used
for turning the soil and clearing the weeds.

Soil
Structure

The structure of soil determines whether air, water and
nutrients can flow freely. A well structured soil has
plenty of pores in a system that allows all of these
through. A poorly structured soil can allow to much water
through thus becoming waterlogged and nutrients may be
lost. Poor structure usually means the soil is too dry in
summer and too wet in winter. Water will either run off
the top or sink in too deep. During wet conditions avoid
walking on the surface or digging as this will compact the
soil and make it too heavy and hard for the plants roots
to get through. It will also cut off the oxygen supply
resulting in zero germination.

Double digging and incorporating additives will help the
soil particles to turn into crumbs which in turn will
improve drainage and aeration. Additives such as manure
and compost are good to use as they encourage natural
workers such as earthworms.

Sandy soil may benefit from small amounts of clay and
heavy soil can be lightened by using vast quantities of
sand and grit. Clay soil will benefit from using manure
and compost. Silt soil may need small amounts of clay and
manure. When using additives ensure you are using the
correct ones for the soil you have. Fine sand for example
can block pores in heavy soil causing further problems,
use gravel or coarse sand instead. Ammonia in fresh manure
can damage certain nearby plants, always try to get rotted
or composted manure. If you only have fresh manure put it
on top of the soil in autumn and do not cultivate the soil
over winter. This will give it chance to rot and the
earthworms will help to get it into the soil. When using
garden compost ensure it is not contaminated with virus or
weeds, any such stuff should be burned. Fresh bark, leaves
and straw decompose using nitrogen which they take from
the soil, this must be replaced. Follow manufacturers
guidelines if using bottled or powdered
products.

Water

Watering
is done to ensure the soil is completely recharged and has
enough supplies to last until the next rainfall or watering.
Thorough watering is crucial to ensure the water gets as
deep as possible. Knowledge of your plants and soil will
assist you in knowing how to water, when to do it and how
much to give. Certain plants may be susceptible to drought
during the year, others may be able to go without. Your soil
may be good at retaining water or a lot of it may get lost.
How much it rains is also a factor. Water excess in soils
may be a damaging as them drying out so maintaining the
right balance is crucial. A well structured soil will retain
water as well as letting it flow freely to the plant via its
pores. Different methods of watering include removing some
soil from around the plant and filling with water, or
burying a large pot with drainage holes close to a plant and
filling the pot slowly. Drip feeders and sprinklers also
provide a constant supply of water that is delivered to the
roots gradually. Never water a plant so that you get
puddling, this will cause soil erosion and the majority will
run off from the plant. Clay soils have a large amount of
fine pores that plants may find it hard to get the water
from, this is why they hold the most water. Sandy soils have
larger pores meaning the plants have easier access to the
water in them, they do however drain a lot. Loams are
usually balanced between good drainage and finer pores for
retention. Controlling weeds ensures the water you give is taken by your plants and not the
uninvited ones and mulching the soil improves penetration
of rain and cuts down evaporation.

During the summer it is not
uncommon for the water supply to be less than the water
use. Water deficiency can occur causing problems for the
plant. When a plants growth rate slows it will wilt.
Additives such as manure when dug in can prevent
deficiencies but constant watering is vital. Taking
rainfall measurements each month is a key part of knowing
when best to water however with dramatic climate
conditions being what they are only use the average
numbers you get as a guide. When buying seeds or plants
etc always check the packaging in which they come. The
guides will show you how moist or dry they like to be kept
and critical periods of growth in which more water may be
needed. Drought conditions can even be useful to
some plants by improving flavour of fruits and vegetables,
especially tomatoes. Many plants thrive in drought
conditions such as cacti, agave, lavenders and grey and
silver leaved plants. Grass will tolerate drought, it may
go slightly brown but will return luscious when it next
rains. Summer watering is not needed for grass. Use water
storage areas such as water butts to put back into the
garden natural water which you have collected.

Compacted soil will retain
water too much causing waterlogging. Bog plants love this
sort of soil but others do not as their roots are not able
to function correctly. In particular boggy areas of your
garden where drainage may not be suitable choose plants
that want to be there such as Gunnera
manicata, ferns,
hosta and iris. Mineral deficiencies can occur in wet soil
due to lack of nitrogen. Clubroot also thrives in wet
soil. To improve drainage create ditches so that the water
lying on the top of the soil has somewhere to run into,
additives dug into the soil such as gravel and sharp sand
can help in less severe cases. When severe waterlogging is
found it may be preferable to install a drainage system,
this should be done using professionals.

Nutrients

When your soil is unable to produce the essential
nutrients it needs you may need to replenish its stock
with some additives. These can be chemical, natural or
organic. Plants need macronutrients such as nitrogen,
phosphorous, potassium, magnesium, calcium and sulphur in
large quantities. Micronutrients such as iron, manganese,
copper, zinc, boron, chlorine and molybdenum are needed in
smaller quantities. Most soils only require additives of
nitrogen, potassium and phosphorous. Deficiencies of these
will cause reduced growth and leaf discolouration. Iron
deficiencies will cause leaves to turn brown especially in
the cases where acid plants are being grown in alkaline
soil or being watered with hard water. If you have made
the decision to go organic in your garden it is still
worth sourcing the very best additives you can find.
Compared nutritionally organic matter is less effective
than chemical products but if the batch is good it can
have longer lasting added benefits. One tonne of manure
can deliver 6kg of nitrogen, 1kg of phosphorous and 4kg of
potassium. A chemical solution of the equivalent amounts
is only 30kg. Manures however are bursting with bulky
waste matter that has many micronutrients in its contents,
can give long term nitrogen effects and provides excellent
conditions for earthworms to live in. Green manures which
are plants grown purely for the purpose of digging up and
putting back into the soil are also a good idea for
organic growers. Ensure you pick your plants wisely and
stay away from the invasive ones. Rye grass, borage and
comfrey are good examples. There are many soluble
inorganic mixtures and slow release products on the market
ranging in price, size and manageability but make sure you
pick the right one for your soil and plants and follow the
instructions carefully. Organic mixes of blood, fish
and bone are effective when the eco system in your soil is
thriving. Organisms break down the slow release formulas
and work them into the soil so applying the mixture when
these organisms are dormant ie in cold weather could be
costly and ineffective.

Top
Dressing & Mulching

Used to improve soil conditions by adding
nutrients, reducing water loss and increase of organic
content top dressings and mulches aid in plant growth.
They are placed on the soil surface for purpose or indeed
decoration. The term top dressing is used to describe
additives being used on lawns and soil and secondly to
describe fertiliser applications around plants. Gravel
& bark
is used to provide quick drainage for potted plants
and beds, Using this method around plants such as alpines
not only has a beneficial result but also draws the eye to
the plant when it is surrounded by decorative gravel.
Mulch comes in both organic and inorganic forms. To
prepare for mulching always remove any weeds that may be
lurking otherwise they will draw in all the nutrients that
you need for your plants. Application should take place in
spring when the ground is warm otherwise the mulch will
retain the coldness of the soil through insulation. When
mulching around a particular plant spread the mulch around
the base of the plant and extend out to directly
underneath the outer leaves. Applied loosely the mulch
will retain water, discourage weeds and maintain a regular
temperature. The mulch should be applied 4-6in
deep. If choosing to go organic then coarse bark is the
best choice for you. This will prevent weeds from
sprouting and any that do appear may be pulled out easily.
Peat and garden composts will improve the condition of
your soil when used as mulch but they may provide a better
habitat in which weeds can grow. They will also break down
into your soil easier than bark which means regular
mulching may be needed. Inorganic mulches consist of
plastic sheeting which can be laid out around your plants
and pinned down using pegs. These will not however allow
any water to penetrate through to your soil or allow water
to evaporate upwards through them. When using this method
ensure your soil is not dry or waterlogged. To combat
these problems pierce holes in the sheeting through which
you can water and place additives if needed. Floating
mulches such as fleece rise as your plants grow, they can
also act as protection from pests.

Compost can be found in two forms, garden compost which
consists of decayed animal, plant and food materials and
potting compost which is manufactured specifically for use
in pots and containers. When your garden compost breaks
down to a level where it is dark and crumbly it can be
added to your soil to aid productivity. It is easy to make
your own compost and there are a wide range of products
available to help you. Caddy bins kept in your kitchen are
handy as you can put all skins and peels in without
trekking to your bin each day. Place a biodegradable bag
inside and when it is full place the entire bag and its
contents into your compost bin. Vermicomposting is
the product of using worms to aid in the breakdown of your
compost. Vermicompost is a natural fertiliser, soil
conditioner and is rich in nutrients. Composting worms are
widely available, sometimes sold as bait. Earthworms and
bacteria together play an integral role in the
decomposition of matter. Use on a small scale to turn your
everyday kitchen waste into high quality soil. Creating a
vermicomposting system is easy and inexpensive. When
creating your own compost heap ensure to use matter rich
in nitrogen and carbon. Paper, bark and small amounts of
grass clippings will provide these. Do not compact your
grass clippings as air will not be able to flow freely.

Burn any weeds that have set seed or are about to as they
will infiltrate your compost and contaminate it. Manure is
a good source of nitrogen and will speed the process up.
Your heap or bin should be approx 1 metre wide and high.
Temperatures hit a high in approx 2-3 weeks. Ensure the
compost is turned regularly as this will aid with
breakdown. Your compost should be ready in approx 3
months. Odours emanating from your heap or bin can also
give you an idea as to what is going on in there. A rotten
egg smell shows you compost is lacking in air and a whiff
of ammonia means the nitrogen content is too high. The
John Innes Horticultural Institute of Great Britain first
formulated potting composts in the 1930s. These consisted
of loam based mixes that included coarse sand and peat.
Loam free composts came onto the market in the
1960s.Always ensure when buying potting composts that the
product you are buying is suitable for the type of
planting you are doing. Loam based composts provide longer
growth rates than their loamless counterparts. They are
free draining, provide a stream, of nutrients steadily,
have good aeration and are structurally sound.
Transplanted plants from loam based composts grow more
readily into the soil. Loamless composts have good
aeration and moisture retention and are long lasting. They
do however break down more easily than loam based composts
meaning that the some of the volume of the compost gets
lost taking with it its basic structure. They do not hold
nutrients quite so well either meaning that your plants
will need to be fed more, and transplanted plants may find
it harder to adapt to their new conditions. Using peat
based composts are environmentally unsound as they are
taken from habitats where the peat supply is depleting.
The need may arise for the use of a specific compost to
aid in growing particular plants. You can almost guarantee
that what you are looking for is on the market. Orchids
for example have their own compost that contain charcoal
and fine bark, this makes it free draining. Cactus and
alpine composts lack in nutrients as that is what the
plant requires for healthy growth. Certain lime hating
plants may require ericaceous compost as they have a low
pH. There are also a wide range of propagation compost
designed specifically to aid in germination. Check the
packaging of these to find out which one is best for
you.